1. Field of the Invention
The present invention relates to the field of typodonts and more particularly to typodonts having one or more removable teeth which can be locked into place by a single locking ring.
2. Prior Art
Typodonts now in use can be divided into two categories. The first category includes typodonts wherein the individual teeth are fixed in place and cannot be removed. These typodonts are used primarily for teaching anatomy and the like. The second category includes typodonts having one or more removable teeth. These typodonts can be used not only for teaching anatomy, but also for the purpose of teaching methods of repairing defective teeth such as methods of filling cavities caused by tooth decay and the like. In such cases a removable tooth having a simulated defect such as a cavity is inserted into the typodont. The student then makes the necessary repairs on the removable tooth and returns the typodont to the instructor for evaluation. The typodont can be reused by replacing the repaired tooth with a new tooth.
The removable teeth of the typodonts now in use are secured within the typodont in a variety of ways. Typically, each removable tooth is provided with a spherical protuberance or ball located at the bottom of the tooth. The typodont is in turn provided with a plastic sheet or the like having a plurality of spaced-apart openings, each having a diameter somewhat smaller than that of the ball on the end of each of the removable teeth. The plastic sheet is positioned within the typodont such that one of the sheet openings is located at the bottom of each of the larger openings which receive the removable teeth. When a removable tooth is to be inserted into the typodont, the tooth is placed in the appropriate opening and a downwardly directed force is applied, thereby causing the tooth to snap into place when the ball on the lower end of the tooth passes through the opening in the plastic sheet. Since the opening in the sheet is slightly smaller than the ball, the tooth will be retained in the typodont. Removal of the teeth in the prior art typodont is accomplished by grasping a tooth firmly and pulling upwardly. This causes the ball on the tooth to pass through the opening in the sheet thereby freeing the tooth from the typodont.
The prior art typodont just described permits a single removable tooth to be replaced with relative ease. However, such typodonts do possess several shortcomings. First, the removable teeth do not always remain properly aligned in the typodont when substantial forces are applied by dental tools or the like. Second, each removable tooth is retained in place by a separate retaining means. Removal and replacement of several removable teeth can be time consuming. Furthermore, in examination applications it is desirable to seal the removables in place using sealing wax or the like for the purpose of preventing unauthorized removal and substitution. The prior art typondonts require that each removable be separately sealed which is cumbersome and not always practical.
A typodont having removable teeth which remain properly aligned even when large forces are applied to the individual teeth would be highly desirable. Also, a typodont having a single locking means which permits all of the removable teeth to be locked in place and unlocked simultaneously would be advantageous in that one or more of the teeth could be effortlessly substituted. Furthermore, a single locking ring or pin could be easily sealed for examination purposes and would obviate the necessity of separately sealing each removable tooth.